1. Field of the Invention
This invention relates to camera systems and more particularly to camera systems composed of a camera, a motor drive unit for automatically winding the camera, and a strobe unit.
2. Description of the Prior Art
Camera stroboscopes, other than special stroboscopes, such as those using rectifier transformer arrangements with a commercial electrical power source and those using layer-built cells, conventionally require an electrical power source or a battery of small bulk and size. As a result, the charging cycle of a strobe unit, starting with emission of a flash and terminating with completion of recharging, takes a relatively long time. As the battery degrades, the required time becomes progressively longer. Therefore, using strobe units with systems taking a continuous succession of exposures, the photographer must wait for the recycle time of the strobe unit and make sure that the storage capacitor is fully charged after each exposure before releasing the shutter. This may annoy the photographer.
Another problem arises when the strobe unit is used with a camera operating with a motor drive unit for automatically winding the film. The motor drive unit winds the film one frame very quickly. If the recycle time of the strobe unit cannot follow at the same speed, photographs may be taken randomly illuminated with flash or ambient light. Thus, all efforts at a continuous succession of flash exposures may be in vain.
U.S. Pat. No. 4,086,603, issued Apr. 25, 1979 allows for a continuous succession of flash exposures using the combination of a camera with a motor drive unit and a strobe unit. This patent proposes a camera system which assures that actuation of each shutter release is made possible only after completion of the winding of the camera by the motor drive and recharging of the strobe unit. In this system, the signal representing the fact that the strobe unit has been fully charged is applied to the motor drive unit where a circuit actuates a shutter release. Therefore, when the system operates without the motor drive unit or when the camera is wound manually, it is no longer possible to assure that the shutter is released only after the camera is cocked and the strobe unit fully recharged. In other words, when the camera is switched into the manual winding mode, the system is no longer useful because a camera release is possible whether or not the strobe unit is fully charged.
Conventional camera systems having a strobe unit of the grip type attached through the motor drive unit to the camera generally use a code to connect a release button on the grip of the strobe unit and a remote control terminal of the motor drive unit so that a shutter release can be actuated by using the release button in the grip of the strobe unit. However, this gives rise to the following problem.
In such conventional camera systems, two codes are necessary, namely the X sync code which connects the camera and the strobe unit with each other, and a release control code which connects the strobe unit and the motor drive unit with each other. In motorized, rapid-sequence operation which requires the photographer to act quickly, the codes may interfere with his handling of the camera, and in extreme cases, the code is plugged out. Thus, there is a great possibility of the shutter being released without the strobe unit firing.